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Classification of Wetlands and Deepwater Habitats of the United States
Abstract
This classification, to be used in a new inventory of wetlands and deepwater habitats of the United States, is intended to describe ecological taxa, arrange them in a system useful to resource managers, furnish units for mapping, and provide uniformity of concepts and terms.Wetlands are defined by plants (hydrophytes), soils (hydric soils), and frequency of flooding. Ecologically related areas of deep water, traditionally not considered wetlands, are included in the classification as deepwater habitats. Systems form the highest level of the classification hierarchy; five are defined—Marine, Estuarine, Riverine, Lacustrine, and Palustrine. Marine and Estuarine Systems each have two Subsystems, Subtidal and Intertidal; the Riverine System has four Subsystems, Tidal, Lower Perennial, Upper Perennial, and Intermittent; the Lacustrine has two, Littoral and Limnetic; and the Palustrine has no Subsystems.
... Mean annual precipitation ranges from its highest at 1,180 mm in the Central Appalachians to its lowest at 1,063 mm in the Western Alleghany Plateau (Wilken et al. 2011). Sampled wetlands were palustrine emergent (n = 7), scrub-shrub (n = 6), and forested (n = 1) but typically exhibited traits of all three dominant vegetation types (Cowardin et al. 1979;Noe et al. 2022). Many palustrine emergent wetlands were younger, although this wetland class was not exclusive to young wetlands. ...
... On four occasions, WVWRAM field assessments came after our field sampling, although these were always ≤ 2 months later. We also used the National Wetlands Inventory (NWI) GIS layer created by the U.S. Fish and Wildlife Service to assess wetland size and type of wetlands (Cowardin et al. 1979;U. S. Fish and Wildlife Service 2014). ...
... We then used the Akaike information criterion (AIC) to compare models and perform a model selection for the top environmental variable (Akaike 1973), specifically AICc, a version of AIC that is corrected for small sample sizes (Brewer et al. 2016). We were limited to one predictor Palustrine emergent, scrub-shrub, and forested according to Cowardin et al. (1979). Vegetation Community Vegetation community was estimated using a principle component analysis (PCA). ...
Small mammals are important, albeit often overlooked, fauna in wetland restoration projects. However, it is essential to evaluate factors that influence small mammal community metrics in restored wetlands to maximize wetland restoration effectiveness. Previous studies found that vegetation differed as restored wetlands aged and that wetland age may play a role in the presence of amphibians and birds. Therefore, we assessed whether wetland age influenced small mammals. We
also evaluated 17 environmental factors in restored wetlands that could influence small mammal communities in these wetlands. To assess and evaluate the effects of age and environmental factors on the small mammal community, we appraised 14 restored wetlands in West Virginia, USA, in the summers of 2020 and 2021 for small mammal community metrics, specifically relative abundance, diversity, richness, and evenness. We captured six species of small mammals: deer mice (Peromyscus
maniculatus), white-footed mice (Peromyscus leucopus), meadow voles (Microtus pennsylvanicus), meadow jumping mice (Zapus hudsonius), northern short-tailed shrews (Blarina brevicauda), and eastern chipmunks (Tamias striatus). We found that the relative abundance of deer mice, white-footed mice, and meadow voles decreased with wetland age. However, both species diversity and evenness increased with wetland age. Wetland size influenced the relative abundance of white-footed mice, meadow jumping mice, and all small mammals combined. Although the relative abundance of white-footed mice and total small mammals decreased with wetland size, the relative abundance of meadow jumping mice increased with wetland size. Wetland managers should consider wetland age and
size when designing wetlands to facilitate small mammal communities.
... Our study sites were lowland brushland systems, which include shrub-carr (Curtis 1959), scrub-shrub (Cowardin et al. 1979), wet meadow-carr (MNDNR 2003), and shrub swamp (Faber-Langendoen 1998). Some sites consisted of palustrine scrub-shrub broad-leaved deciduous wetlands (Cowardin et al. 1979). ...
... Our study sites were lowland brushland systems, which include shrub-carr (Curtis 1959), scrub-shrub (Cowardin et al. 1979), wet meadow-carr (MNDNR 2003), and shrub swamp (Faber-Langendoen 1998). Some sites consisted of palustrine scrub-shrub broad-leaved deciduous wetlands (Cowardin et al. 1979). Fires occurring during different times of the year likely contributed to the mix of herbaceous and woody plants in intact brushlands because season of fire affects fire intensity, severity, behavior, and the response of plant communities (Platt et al. 1988, Sparks et al. 1999, Knapp et al. 2009, Weyenberg and Pavlovic 2014. ...
... Our findings for chestnut-sided warblers and yellow warblers do not align with those reported by Confer and Pascoe (2003), who reported that in the eastern Great Lakes region both species were associated with lowstature shrubs, although they did not provide heights and our sites may have had woody plants of lower average height (Table 2). Lowland brushlands include more low-stature woody species (e.g., leatherleaf, Labrador tea, and bog laurel [Kalmia polifolia]) than upland brushlands (Cowardin et al. 1979, MNDNR 2003; therefore, it may be necessary to quantify height differences among brushland vegetation communities to understand inconsistencies in bird-habitat associations among studies (Schlossberg et al. 2010). ...
Brushlands support a diverse suite of bird species, including species of conservation concern in the western Great Lakes region of central North America. Information on how to effectively manage lowland brushlands for birds and associations between breeding birds and local‐scale vegetation structure and composition is lacking. We surveyed lowland brushlands from 2016-2018 in Minnesota, USA, to assess bird‐habitat associations using avian point‐count surveys and fixed‐radius vegetation plots. We used Poisson regression models to assess the associations between breeding bird species richness, total abundance, and abundance of frequently detected species (using counts as an index for abundance) to woody stem density and height, patchiness of woody stem density, variation of woody stem height, and number of woody plant species. Sedge wrens (Cistothorus stellaris), the most abundant species, were negatively associated with multiple woody plant metrics and positively associated with patchiness. Common yellowthroats (Geothlypis trichas) were the second‐most abundant species and associated with low‐stature woody plants (<1 m based on average heights in study sites). Bird species richness, alder flycatchers (Empidonax alnorum), chestnut‐sided warblers (Setophaga pensylvanica), swamp sparrows (Melospiza georgiana), veeries (Catharus fuscescens), and yellow warblers (Setophaga petechia) increased with woody vegetation height. Chestnut‐sided warbler and Nashville warbler (Leiothlypis rufica-pilla) abundances also increased with woody stem density. We suggest that managing lowland brushlands to promote diverse woody plant structure, including tall shrubs and areas with patchy, open herbaceous cover, by implementing temporally and spatially variable disturbance regimes, may benefit bird species that rely on lowland brushlands with a range of vegetation structure requirements.
... The ghost forest sites, located in the Albemarle Sound, Alligator River, and Tar River, ranged in average water salinity from 3.51 to 8.32 ppt and spanned the oligohaline and mesohaline zones. The marsh sites, located in the Longshoal River, Swanquarter Bay, Juniper Bay, and on the west edge of the Albemarle-Pamlico Peninsula, ranged in average salinity from 11.73 to 15.47 ppt and were all in the mesohaline range [26]. In addition to the 12 sites where soil physical and chemical data were collected in the field, we examined 33 additional soil map units for additional GIS analysis based on ecosystem, soil type, and fetch throughout the APES (Figure 1). ...
... A spline with tension was applied to the water quality monitoring station points (n = 59) to create a continuous raster for the APES. The interpolated salinity values were grouped into four classes after [26]: tidal fresh (<0.5 ppt), oligohaline (0.5-5 ppt), mesohaline (5-18 ppt), and polyhaline (18-30 ppt). ...
Coastal Zone Soil Survey mapping provides interpretive information that can be used to increase coastal resiliency and quantify how coastal ecosystems are changing over time. North Carolina has approximately 400,500 ha of land within 500 m of the tidal coastline that is expected to undergo some degree of salinization in the next century. This study examined 33 tidal wetlands in the Albemarle–Pamlico Sound along a salinity gradient to provide a coastal zone mapping framework to quantify shoreline change rates. The primary ecosystems evaluated include intact tidal forested wetlands (average water salinity, 0.15–1.61 ppt), degraded “ghost forest” wetlands (3.51–8.28 ppt), and established mesohaline marshes (11.73–15.47 ppt). The average shoreline rate of change (m/yr) was significantly different among estuary ecosystems (p = 0.004), soil type (organic or mineral) (p < 0.001), and shore fetch category (open or protected) (p < 0.001). From 1984 to 2020, a total of 2833 ha of land has been submerged due to sea level rise in the Albemarle–Pamlico Sound with the majority (91.6%) of this loss coming from tidal marsh and ghost forest ecosystems. The results from this study highlight the importance of maintaining healthy coastal forests, which have higher net accretion rates compared to other estuarine ecosystems.
... The NWI classifi cation system (Cowardin et al. 1979 Most Montana wetlands are Palustrine. This System generally includes any wetlands not within a stream or river channel (Riverine System) or within bodies of water which are either larger than 20 acres OR deeper than 6.6 feet (Lacustrine System). ...
... System includes any wetlands not within a stream or river channel (Riverine System) or within bodies of water which are either > 20 acres OR deeper than 6.6 feet (Lacustrine System). See Cowardin et al. (1979) for complete details on the NWI classifi cation system. Nine possible Classes in the Palustrine System exist. ...
... Aerial imagery was accessed across several decades via Google Earth Pro version 7.3 using the "time slider" tool, which aided in confirming wetland presence and classification (Google, 2018). Palustrine wetlands included shallow non-tidal wetlands which can have emergent vegetation or open-water forms and are saturated or inundated for a significant portion of the growing season annually (Cowardin et al., 1979;Tiner, 2016). These wetlands tend to fluctuate in water level seasonally, vary in hydroperiod length, and dry out to varying degrees and frequencies. ...
... Any palustrine wetland that was modified to increase wetland hydroperiod (i.e., impounded, excavated, or diked) was categorized separately (PAL-IMP). Lacustrine wetlands (LAC) were primarily deep-water wetlands >8 ha in size or deeper than 2.5 m at low water with <30% coverage of vegetation (Cowardin et al., 1979;Tiner, 2016); impounded lacustrine wetlands, including reservoirs, were categorized separately (LAC-IMP). Riverine wetlands (RIV) were lotic systems of all flooding frequencies, but generally included intermittently and permanently flooded designations. ...
Wildlife species confront threats from climate and land use change, exacerbating the influence of extreme climatic events on populations and biodiversity. Migratory waterbirds are especially vulnerable to hydrological drought via reduced availability of surface water habitats. We assessed how whooping cranes (Grus americana) modified habitat use and migration strategies during drought to evaluate their resilience to changing conditions and adaptive capacity. We categorized >8000 night‐roost sites used by 146 cranes from 2010 to 2022 and examined relative use during non‐drought, moderate drought, and extreme drought conditions. We found cultivated and uncultivated palustrine and lacustrine wetlands were generally used less during droughts than non‐drought conditions. Conversely, impounded palustrine and lacustrine systems and rivers served more frequently as drought refugia (i.e., used more during drought than non‐drought conditions). Night roosts occurred primarily on private lands (86% overall); public land use decreased with latitude and increased with drought severity, with greatest use (56%) occurring during severe autumn drought in the southern Great Plains. Quantifying use of identified critical habitats in the United States indicated that Cheyenne Bottoms State Waterfowl Management Area and Quivira National Wildlife Refuge were used less during drought, and the Central Platte River and Salt Plains National Wildlife Refuge received similar use during drought compared to non‐drought conditions. Our findings provide insights into compensatory use of habitats, where impounded surface water may function in a complementary fashion with natural wetlands. Collectively, these and other types of wetlands distributed across the migration corridor provided a reliable network of habitat available across the Great Plains. A diversity of wetlands available during variable environmental conditions would be useful in supporting continued recovery of whooping cranes and likely have benefits for a wide array of migratory birds.
... The vegetated tidal delta is exposed to tidal and riverine processes and dominated by three tidal wetland types or zones: forested riverine tidal (FRT), estuarine forest transition (EFT), and estuarine emergent marsh (EEM) (after Cowardin et al. 1979). Because these wetland types are determined by their location relative to fluvial and tidal inundation, they have different abiotic and biotic characteristics. ...
... We characterized the tidal wetland type of each site, based on indicator habitat types (Fig. 1, Supplemental text and Table S1). We used aerial photographs to determine the dominant vegetation type, following the classifications of Cowardin et al. (1979). Sites were also evaluated in the field to verify aerial photograph interpretations, and the presence/absence of indicator vegetation provided a qualitative evaluation of photogrammetric classification. ...
Habitat restoration planning and design can be informed by information on spatial patterns in habitat use, which can be obtained from temporally and spatially extensive monitoring efforts. Using records from long-term monitoring in four tidal deltas, we modeled how landscape features (channel types, wetland vegetation types, and a channel network connectivity index) influenced juvenile natural-origin (NOr) and hatchery-origin (HOr) Chinook salmon presence/absence and density when present. Models detected strong effects of landscape characteristics on either presence/absence or density, although the directionality and relative importance of these features differed between NOr and HOr fish. In addition, while interannual differences were stronger for NOr juveniles, the seasonal pattern was much stronger for HOr fish and was in fact the strongest predictor of density. For both types of fish, interactions between landscape features and seasonal pattern existed, indicating that habitat use changed dynamically from the beginning to the end of the rearing period. These findings help provide general principles for prioritizing location and designing habitat restoration projects.
... Wetlands also play a vital role in mitigating the impacts of climate change by storing carbon and reducing greenhouse gas emissions. However, as Cowardin L M [15] notes that, wetlands are highly vulnerable to human activities and are rapidly disappearing, making their conservation a critical priority. ...
... The significance of wetlands in providing ecological benefits such as water purification and flood control has been widely acknowledged by various sources [4,9,11,15,16,17]. Wetlands are crucial in supporting the lives and livelihoods of countless individuals worldwide. ...
... In wetland systems, plants are spatially organized in a zonation pattern in which the arrangement and distribution of species is closely tied to water level (Cowardin et al., 1979;Hopkinson, 1992;Keddy, 2010;Mitsch and Gosselink, 2015;Korasidis et al., 2017). This pattern reflects physiological and ecological responses, such as the tolerance of plants to particular microhabitats (e.g., soil moisture and chemistry, shading, competition with other taxa, among other factors), and the plants' ability to recover from, or to recolonise following, burial and mass erosion events associated with flooding. ...
... Erect ferns (e.g., Marattiales: Cyclogranisporites, Verrucosisporites), requiring relatively longer periods of growth for maturation than their smaller counterparts, probably thrived in the more sheltered regions within these disturbed zones, such as raised, stable banks, along the fringes of active channels, or sandbar tops within fluvial streams, which inundated less frequently (e.g., Cowardin et al., 1979). Conversely, sphenophytes (Calamospora, Laevigatosporites) would have dominated moist areas with high deposition rates, such as crevasse splays and lower tiers of sandbars, similar to backswamp reeds (Juncaceae, Typhaceae) in modern ecosystems. ...
... A pesar de las dificultades para su definición, desde un punto de vista ecológico un humedal es un ecosistema que se caracteriza por tres atributos clave: la presencia de agua, condiciones particulares del suelo (muchas veces saturado de agua) y una biota adaptada a condiciones de alta humedad (Mitsch & Gosselink, 2015;Cowardin et al., 1979). El componente más relevante de un humedal es su hidrología, que determina las condiciones fisicoquímicas del sustrato y del agua, y ambas condicionan la biota que puede existir en estos ambientes (Mitsch & Gosselink, 2015). ...
... El componente más relevante de un humedal es su hidrología, que determina las condiciones fisicoquímicas del sustrato y del agua, y ambas condicionan la biota que puede existir en estos ambientes (Mitsch & Gosselink, 2015). De acuerdo con Cowardin et al. (1979), una de las definiciones más ampliamente utilizadas, un humedal se reconoce por cumplir alguno de estos tres atributos: 1) presencia de vegetación predominantemente hidrófita al menos en algún periodo del año, 2) sustrato dominado por suelo hídrico (con mal drenaje o sin drenaje), y 3) sustrato saturado o cubierto con agua superficial en algún momento de la temporada de crecimiento vegetacional. Estos atributos generalmente son incluidos en las diversas definiciones de humedales que existen, aunque esto no siempre se cumple como veremos en la siguiente sección. ...
In Chile there is a growing social appreciation of wetlands, expressed in conflicts and local movements that seek the protection of these ecosystems. The interpretation of a “wetland” definition and its application to different geographical contexts, to determine whether measures for their protection are necessary, has been at the center of these socio-environmental conflicts. We use a legal geography approach based on case studies to shed light on how the Ramsar Convention definition of “wetlands” has been used in three of the main jurisdictional instances for environmental dispute resolution in Chile: application for amparo, the Environmental Courts and the Office of the Comptroller General of Chile. We find that, while the Supreme Court has used a broad interpretation requiring only that an ecosystem meets the Ramsar Convention wetland definition to be protected -regardless of its official protection status- other instances such as the Environmental Courts and the Comptroller General of the Republic have been more restrictive demanding wetland official protection to regulate activities that may affect these ecosystems. This has practical consequences for the legal options and strategies used by those seeking to promote or limit wetland protection.
... Estimates indicate that 10% of the identified species of the planet (130,000 species) occur in continental wetlands, although these habitats cover less than 1% of the earth's surface (Dijkstra et al. 2014). Such high species diversity is a consequence of the different wetland types that exist in the world, from marine to coastal to continental, including the human-made ones (Cowardin et al. 1979). Furthermore, habitat variations such as depth, aquatic plant types, size, and hydroperiod also contribute to the high species diversity of these ecosystems (Guadagnin and Maltchik 2007;Rolon and Maltchik 2006;Stenert and Maltchik 2007). ...
... The diversity of wetland types makes it difficult to develop a single definition that encompasses all wetland ecosystems . Therefore, researchers suggest that the basic definition of wetlands is related to their key attributes: presence of water, hydromorphic soils, and water-adapted biota (Cowardin et al. 1979). In Brazil, Junk et al. (2014) proposed a definition based on those attributes. ...
Wetlands are among the most productive ecosystems on the earth, with enormous ecological and social importance. Here, we cover most of the recent knowledge produced in relation to the wetland ecosystems of Pampa and South Brazilian highland grasslands (Campos Sulinos). We review the main drivers of the biodiversity of small wetlands; the contribution of specific land-management practices to wetland-dependent wildlife; the importance of dispersal processes to the biodiversity of isolated wetlands; the occurrence of endemic and endangered annual fish species; and the importance of restoration initiatives in impacted wetlands. Finally, we provide some suggestions that provide relevant information to wetland conservation and management in the Campos Sulinos. The wetlands of the Campos Sulinos present high biological diversity for different groups of organisms (invertebrates and vertebrates). The conservation of the wetlands will guarantee the maintenance of a large part of the region’s biological and genetic diversity and will provide natural resources to local human population. In addition, the conservation of wetlands will provide leisure and recreation areas for the urban population, and minimize the negative impacts that floods bring to large- and medium-sized cities.
... Wetlands in these products are mapped as either estuarine or palustrine and by wetland vegetation type (i.e., aquatic bed, emergent herbaceous, scrub/shrub, and forested; NOAA, 2016b). Estuarine wetlands are tidal wetlands that include areas with a salinity of at least 0.5 ppt, whereas palustrine wetlands include tidal and non-tidal wetlands that have a salinity that is less than 0.5 ppt (Cowardin et al., 1979). The US Fish and Wildlife Service's National Wetland Inventory (NWI) provides the most comprehensive information on wetlands in the US (USFWS, 2022). ...
... Wetland inundation mapping. As previously mentioned, we used the estuarine wetland class, which have a salinity greater than 0.5 ppt (Cowardin et al., 1979), to represent estuarine wetlands. Estuarine wetlands in this classification include areas that are regularly exposed to saline waters (i.e., from high tides) and irregularly exposed to saline water (i.e., less than daily though regular tides, perigean spring tides, wind-induced water fluctuations, and storms). ...
Over the coming century, climate change and sea-level rise are predicted to cause widespread change to coastal wetlands. Estuarine vegetated wetlands can adapt to sea-level rise through both vertical development (i.e., biophysical feedbacks and sedimentation) and upslope/horizontal migration. Quantifying changes to estuarine vegetated wetlands over time can help to inform current and future decisions regarding land management and resource stewardship. In this study, we show how coastal land cover maps readily available in the US can be used to assess and understand estuarine vegetated wetland changes. This assessment involves two steps: (1) identifying the net gain/loss of estuarine vegetated wetlands and (2) determining which land cover types contribute to the net gain/loss. From this information, we developed estuarine vegetated wetland change scenarios that evaluate whether estuarine vegetated wetland gain kept up with loss and whether the contribution was from: (1) estuarine vegetated wetland migration or tidal restoration; (2) land building (i.e., development); or (3) both. We assessed changes from 1996 to 2016 for: (1) the conterminous US; (2) each major US coastline; and (3) focal estuaries with the most change per coast. We found that the change scenario (1, 2, or 3) varied across coastlines. Moving forward, national coastal land cover programs can be informed by utilizing methodologies that leverage contemporary information for delineating the estuarine zone from upslope/adjacent wetlands. We highlight approaches that could be used to address this challenge and provide complementary information related to wetland condition changes.
... Wetland classifications used in this study (Bergman et al., 1977) compared to the classification of Cowardin et al. (1979). However, not all wetland locations were adequately joined, and in some cases, data from multiple classified wetlands were joined to a single polygon. ...
... Terms in parentheses for the Cowardin classification are included to avoid ambiguity for some wetland types.Basin complexes contain multiple smaller wetlands of various types, and are present only early in the season, after which water levels recede and smaller wetlands become distinct from one another. No equivalent wetland type exists in theCowardin et al. (1979) classification system.Deep Carex wetlands, ditches, and man-made basins were not included in theBergman et al. (1977) classification but were added, as these habitat types are present in our study area and may be used by sea ducks. Analyses apply only to the use of non-anthropogenic wetland types. ...
Wetlands in Arctic tundra support abundant breeding waterbirds. Wetland types differing in area, depth, vegetation, and invertebrate biomass density may vary in importance to birds, and in vulnerability to climate change. We studied availability and use of different wetland types by prelaying females of four species of sea ducks (Mergini) breeding on the Arctic Coastal Plain of Alaska, USA: long-tailed ducks (Clangula hyemalis) and Steller's (Polysticta stelleri), spectacled (Somateria fischeri), and king eiders (Somateria spectabilis). All four species preferred shallow vegetated wetlands versus deeper lakes. The ducks spent almost all their active time feeding, but their occurrence in different wetland types was not affected by the relative biomass density of known prey or of all invertebrates that we sampled combined. Sea ducks strongly preferred wetlands dominated by emergent and submersed Arctophila fulva over those dominated by the sedge Carex aquatilis, despite the much greater number , total area, and invertebrate biomass density of Carex wetlands. The hens depend heavily on local invertebrate prey for protein to produce eggs; thus, their preference for Arctophila wetlands likely reflects greater accessibility of prey in the near-surface canopy and detritus of Arctophila. Such shallow wetlands decreased substantially in number (−17%) and area (−30%) over 62 years before 2013 and appear highly susceptible to further declines with climate warming. Impacts on sea ducks of climate-driven changes in availability of important wetland types will depend on their adaptability in exploiting alternative wetlands.
... Trained image analysts manually delineated these polygons from aerial and fine resolution satellite imagery. Wetland experts then determined the attributes of these polygons, such as information about the wetland substrate type, vegetation type, water regime type, and water chemistry type, based on their assessments of field sampling data and the Cowardin wetland classification system [14,32]. The NWI dataset for the study area was obtained from the U.S. Fish and Wildlife Service Wetlands Mapper in July 2021 [33]. ...
... Water regime codes and their full names[32]. ...
The National Wetlands Inventory (NWI) is the most comprehensive wetland geospatial dataset in the United States. However, it can be time-consuming and costly to maintain. This study introduces automated algorithms and methods to support NWI maintenance. Through a wall-to-wall comparison between NWI and Coastal Change Analysis Program (C-CAP) datasets, a pixel-level difference product was generated at 1 m resolution. Building upon this, supplementary attributes describing wetland changes were incorporated into each NWI polygon. Additionally, new water polygons were extracted from C-CAP data, and regional statistics regarding wetland changes were computed for HUC12 watersheds. The 1 m difference product can indicate specific wetland change locations, such as wetland loss to impervious surfaces, the gain of open water bodies from uplands, and the conversion of drier vegetated wetlands to open water. The supplementary attributes can indicate the amount and percentage of wetland loss or water regime change for NWI polygons. Extracted new water polygons can serve as preliminary materials for generating NWI standard-compliant products, expediating NWI maintenance processes while reducing costs. Regional statistics of wetland change can help target watersheds with the most significant changes for maintenance, thereby reducing work areas. The approaches we present hold significant value in supporting NWI maintenance.
... Coastal TAIs are critical interfaces between the land and ocean where freshwater and seawater mix , thus playing a pivotal role in global biogeochemical cycles (Enguehard et al., 2022). We define the coastal TAIs as the part of coastal zones along the gradient of coastal uplands (e.g., forests and grasslands), wetlands, and surface waters, where complex interactions among hydrologic, biogeochemical, and ecological processes take place to control the carbon and nitrogen cycling under highly dynamic and heterogeneous redox conditions (Assessment, 2005;Chmura et al., 2003;Costanza et al., 1997;Cowardin et al., 1979;Michael et al., 2005;Mitsch & Gosselink, 2007;Thorne & Williams, 1997). Developing a mechanistic understanding of the bidirectional exchange fluxes and nutrient cycling at the coastal TAIs is critical for explicitly representing them in Earth system models to more accurately quantify global carbon budget and evaluate ecosystem resiliency and resistance to climate changes (Casas-Ruiz et al., 2023;Kolka et al., 2021;Regier et al., 2021;Tank et al., 2018;Ward et al., 2020). ...
Plain Language Summary
The hydrological environment of vegetated coastal ecosystems is directly influenced by precipitation and seawater flooding, which mediates biogeochemical processes within these areas. However, the specific effects of dynamic precipitation and flooding on oxidation‐reduction conditions in these complex terrestrial‐aquatic interfaces (TAIs) are poorly understood, especially when considering the ecological processes of above‐ground plants. To address this gap, this study used integrated process‐based models, the Advanced Terrestrial Simulator (ATS) and PFLOTRAN, to examine the effects of hydrological and ecological controls on biogeochemical reactions and exchange fluxes across a TAIs transect spanning from a coastal upland forest and salt marsh to the open seawater. Our numerical experiments showed that the mixing of different waters within the TAIs significantly influenced the spatial and temporal variability in exchange fluxes across this interface along with the spatial extent of oxic subsurface zones. The interface between the oxic and anoxic zones shifts in response to periodic fluctuations in tidal elevations as higher tides drive more oxygenated water toward the TAIs. Meanwhile, vegetation evapotranspiration removes more water from the subsurface during warm summer months, leading to larger exchange fluxes across the TAIs. Reaction rate parameters that depend on the interactions between the soil and microbes have a large effect on carbon and oxygen consumption represented in our models. A higher aerobic respiration rate results in larger hypoxic and anoxic zones because the dissolved oxygen is consumed more quickly. Our modeling‐based study provided insights into the mechanisms that control the exchange fluxes and cycling of carbon and nitrogen at coastal TAIs, which can be used to inform potential management strategies for mitigating the impacts of climate change on these ecosystems.
... These wetlands are exposed to oceanic waters less frequently than daily via extreme spring tides, perigean spring tides, wind-induced water level fluctuations, and storms. Regularly oceanic-flooded wetlands (hereafter regularly flooded wetlands) are located above the mean lower low water and below the mean high water tidal datums (Cowardin et al. 1979). These wetlands are exposed to oceanic waters daily through tides. ...
Sea-level rise rates are predicted to surpass rates of wetland vertical adjustment in the coming decades in many areas, increasing the potential for wetland submergence. Information on where wetland migration is possible can help natural resource managers for planning land acquisition or enhancing habitat connectivity to bolster adaptation of coastal wetlands to rising seas. Elevation-based models of wetland migration are often hampered with uncertainty associated with ground surface elevation, current water levels (i.e., tides and extreme water levels), and future water levels from sea-level rise. Here, we developed an approach that involved digital elevation model error reduction and the use of Monte Carlo simulations that utilize uncertainty assumptions regarding elevation error, contemporary water levels, and future sea levels to identify potential wetland migration areas. Our analyses were developed for Duvall and Nassau Counties in northeastern Florida (USA). We focus on the migration of regularly oceanic-flooded wetlands (i.e., flooded by oceanic water daily) and irregularly oceanic-flooded wetlands (i.e., flooded by oceanic water less frequently than daily). For two relative sea-level rise scenarios based on the 0.5 m and the 1.5 m global mean sea-level rise scenarios, we quantified migration by wetland flooding frequency class and identified land cover and land use types that are vulnerable to future exposure to oceanic waters. The variability in total coverage and relative coverage of wetland migration from our results highlights how topography and accelerated sea-level rise interact. Our wetland migration results communicate uncertainty by showing flooding frequency class as probabilistic outputs.
... Wetlands are transitional lands between terrestrial and aquatic systems where the water table is usually at or near the land surface, or is covered by shallow water 8 . Wetlands have a greater effect on the quality and quantity of GW 9 . ...
... Climate norms are typically calculated at 30-year intervals; however, this approach made it possible to represent recent ecological conditions (sensu Donnelly et al., 2022) while reducing the influence of weather-induced outliers occurring during the study period. Using standards similar to Cowardin et al. (1979), surface water conditions were classified into hydroperiods by totaling the months individual pixels were inundated from January to December. Hydroperiod is a key delimiter of wetland function important to determining ecological values (sensu Minckley et al., 2013). ...
Ranching in the American West has long relied on riparian ecosystems to grow grass-hay to feed livestock in winter and during drought. Producers seasonally flood grasslands for hay production using stream diversions and low-tech flood-irrigation on riparian floodplains. Inundation mimics natural processes that sustain riparian vegetation and recharge groundwater. The recent doubling in use of more efficient irrigation approaches, such as center-pivot sprinklers, threatens to accelerate climate change impacts by unintentionally decoupling more inefficient, traditional practices that sustain riparian systems. To assess ecosystem services provided by flood-irrigation hay production, we developed an exhaustive spatial inventory of grass-hay production and combined it with monthly surface water distributions modeled from satellite data. Surface water data were classified by wetland hydroperiod and used to estimate the proportion of wetlands supported by grass-hay production in the Intermountain West, USA. Elevation and proportion of grass-hay relative to other irrigated lands were enumerated to examine differences in their positions and abundance within landscapes. Lastly, we overlaid the delineated grass-hay wetlands with LANDFIRE pre-Euro-American Settings layer to quantify the efficacy of flood irrigation in mimicking the conservation of historical riparian processes. Findings suggest that inefficient grass-hay irrigation mirrored the timing of natural hydrology, concentrating ~93% of flooded grasslands in historical riparian ecosystems, affirming that at large scales, this ranching practice, in part, mimics floodplain processes sustaining wetlands and groundwater recharge. Despite representing only 2.5% of irrigated lands, grass-hay operations supported a majority (58%) of temporary wetlands, a rare and declining habitat for wildlife in the Intermountain West. Tolerance for colder temperatures confined grass-hay production to upper watershed reaches where higher value crops are constrained by growing degree days. This novel understanding of grass-hay agroecology highlights the vital role of working ranches in the resilience and stewardship of riparian systems.
... According to Cowardin et al. (1979), wetlands are the places where terrestrial and aquatic ecosystems meet. They may be identified by the existence of a water table, which is often at or near the surface or submerged. ...
Globally, wetland ecosystems are vital for supporting biodiversity and provide numerous ecosystem services, with fisheries
playing a pivotal role. Wetlands are essential nurseries for fish, supporting fisheries that contribute significantly
to food security and livelihoods. Wetlands offer a consistent supply of water, which can be well utilized for fisheries and
aquaculture. Groundwater recharge from wetlands is crucial for irrigation, drinking water, and other uses. Additionally,
wetlands control water movement, aiding in the reduction of floods and droughts. They also serve as carbon sinks and
play a crucial role in mitigating climate change. However, wetlands face multiple risks, including habitat destruction due
to urbanization and agricultural expansion, water pollution, overfishing, and invasive species. Climate change exacerbates
these threats, altering wetland habitats and fish behavior. Sustainable wetland fisheries management is essential
to mitigate these risks, emphasizing the need for community-based approaches, habitat restoration, and the development
of resilient fish populations. The future prospects of wetland fisheries lie in integrated conservation strategies that balance
the ecological significance of wetlands with the socioeconomic benefits to humans. Incorporating traditional ecological
knowledge, scientific research, and policy interventions will be key to safeguarding these ecosystems and ensuring
sustainable fisheries and aquaculture. In the context of the expanding fisheries and aquaculture industries, this study
addresses the significance, risks, and future prospects of wetlands in India.
ADDITIONAL INDEX WORDS: Wetlands, coastal wetlands, aquaculture, livelihood, Ramsar site.
... Setting technically-based wetland structure goals Lakes tend to be surrounded by concentric zones of vegetation, varying by hydroperiod/depth (Cowardin et al. 1992, Keddy and Fraser 2000, SFWMD 2020. The zones tend to be contiguous except when disturbed by wave energy, ice, inflows, and anthropogenic disturbance (e.g., riparian rights). ...
Fish, Wildlife, and Habitat Management Plan for the Kissimmee Chain of Lakes, in central Florida. This plan was authorized by, established goals for, and will direct funding to programs in the Florida Fish and Wildlife Conservation Commission (FWC). FWC is the lead state agency responsible for managing fish and wildlife resources in Florida.
... In addition to the key drivers affecting salt marshes at the global, coastal, inter-system, and intra-system levels listed by Yando et al. (2023), coastal marshes in our study area can be influenced by sea ice (thickness, frequency, movement), soil type, and isostatic land uplift. The Classification of wetland and deepwater habitats used in the USA, the so-called Cowardin system, is also hierarchical and modular and applicable to large geographic regions with varying climate, geology, soil, and vegetation (Cowardin et al., 1979;Federal Geographic Data Committee, 2013). Adaptations of the Cowardin classification are used in various conditions worldwide, and it could work as an example for the harmonized habitat classification in the study area. ...
... By the year 2060, Florida's urban land area is expected to more than double (Zwick and Carr 2006) with predictions suggesting that nearly 50% of the land in central Florida will be developed by 2070 (Carr and Zwick 2016). Palustrine wetlands, nontidal perennial freshwater (<0.5 parts per thousand of ocean-derived salts) wetlands dominated by emergent vegetation (i.e., shrubs, trees, persistent emergents, and emergent mosses or lichens; Cowardin et al. 1979), are the primary wetland type selected by Florida mottled ducks (Bielefeld 2002, Varner et al. 2014. Florida has lost approximately 3.9 million ha (46%) of its historical wetlands; 2.6 million ha of these were palustrine wetlands (Dahl 2004). ...
The nonmigratory and endemic Florida mottled duck (Anas fulvigula fulvigula) is facing conservation threats from the combined effects of urbanization and introgressive hybridization with feral mallards (Anas platyrhynchos) and mallard x mottled duck hybrids. In the past, the status of the Florida mottled duck population was assessed during annual aerial surveys and most brown ducks (mottled ducks, mallards, and hybrids of them) detected during the survey would have been mottled ducks. But the release of domesticated mallards for aesthetic purposes has led to increases in the prevalence of mallards-hybrids (mallards or mallard x mottled duck hybrids) throughout peninsular Florida, USA, and because it is impossible to differentiate among mottled ducks, female mallards, and hybrids during aerial surveys, helicopter surveys were halted in 2009 until state researchers could conduct a range-wide study to determine what proportion of brown ducks are mottled ducks versus mallards-hybrids. We used plumage keys and high-resolution photography to categorize brown ducks from 557 wetland grid points as either mottled ducks or mallards-hybrids. Of the 5,179 brown ducks categorized, 40.1% were mottled ducks and 59.9% were mallards-hybrids. We used logistic regression analysis to model the interactive effect of a site's latitude and level of urbanization (urban gradient value within a 2-km buffer) to generate a predictive raster surface (1-km resolution) of the study area with values corresponding to the probability that a brown duck observed within a cell is a pure mottled duck. Predicted values will be used as correction factors when estimating final mottled duck population abundance from brown‐duck survey data. Additionally, the predictive raster surface will be used to identify wetlands where mottled ducks remain predominant so that these sites can be targeted for preservation. Overall, mallards‐hybrids outnumbered mottled ducks throughout most of peninsular Florida, especially in more urbanized regions, and their current prevalence rate presents a serious conservation threat, via hybridization, to extant mottled duck populations.
... Flow from surrounding areas is scarce. Water depth varies with the seasons: from October to March the flood level reaches the maximum value (70 cm), while from June to October it is reduced to form some areas of muddy soil or shallow ponds , or seasonally flooded wetland sensu Cowardin et al. 1979). The study area shows a specific, semi-natural patchiness. ...
Hemeroby is a concept widely employed in assessment of the effect of human activities on vegetation. In this study, we apply the concept to a set of bird species occurring in a Mediterranean remnant wetland. The aim was to obtain an average hemeroby index for two seasonally related bird assemblages (i.e. breeding and wintering) based on the information related to two levels of plant hemeroby. In a grid of 47 cells 100£100 m-wide, we sampled the fine-grained distribution of plant communities (Braun-Blanquet method6 cell) in parallel with birds (point count method; one point count6 cell), assigning an independent score of hemeroby to plants and birds on a scale from I to V, from pristine habitats with a lack of natural and6 or anthropogenic disturbance (score D I) to completely artificial habitats (score D V). Whereas bird species ranged from categories II to V, vegetation types spanned only the categories III and IV. Therefore, bird species showed a higher variability in hemeroby. By comparing hemeroby scores, we can deduce the effect that the vegetation disturbance may have on bird species. The mean hemeroby for breeding birds, calculated on all the species occurring in a determined plant hemeroby category, is not significantly different between sites with higher (D IV) and lower (D III) plant hemeroby (i.e. higher and lower level of disturbance). The mean hemeroby of the wintering birds was significantly different in the two levels of plant hemeroby (i.e. higher vs. lower hemeroby). Our data suggest that only the wintering birds had a hemeroby distribution pattern related to that of the plants, while the distribution of breeding birds showed no association, i.e. they appear in similar distribution in both plant hemeroby classes. This pattern may reflect the characteristics of the habitat types in relation to bird seasonality: a large section of wintering bird species are strictly water-related, linked to habitats with low plant hemeroby, so appearing more sensitive to change in plant hemeroby when compared to breeding species. Although explorative, our data may be useful in wildlife management, implying that in wetlandÀgrassland mosaics the more sensitive wintering bird species are suitable as indicators aimed to test the effect of natural and anthropogenic disturbances.
... Flow from surrounding areas is scarce. Water depth varies with the seasons: from October to March the flood level reaches the maximum value (70 cm), while from June to October is reduced to form some areas of muddy soil or shallow ponds (Battisti et al. 2004(Battisti et al. , 2006Zacchei et al. 2011; seasonally flooded wetland sensu Cowardin et al. 1979). The study area shows a semi-natural heterogeneity being composed of different patches of reed beds (dominated by Phragmites australis (Cav.) ...
In a Mediterranean patchy wetland of central Italy, we analyzed the relationship between the number of bird species, expressed in terms of bird alpha diversity, and plant alpha diversity, expressed as Hill number. This number (the exponential of the Shannon entropy) is considered one of the most strong and reliable indexes of alpha-diversity, synthesizing the information on evenness, richness and diversity in one single metric. We observed a progressive increase of the mean values of bird alpha diversity when plant alpha diversity increases along Hill number. Bird alpha diversity shows an abrupt increase between the first and the second of four categories of plant alpha diversity (0-1, [1-2, [2-3, [3), indicating a threshold response in all the groups considered (breeding, wintering and total bird assemblages). This marked decline of bird species richness at around 1 in the Hill index should represent an alarm for managers: wetland sites at or below this level of plant alpha diversity are likely to be experiencing a drastic decrease in bird species richness, both in spring (breeding birds) and in winter (wintering birds).
... In the artificial channels water level varies in space and time. Around a yearly cycle, water depth is maximum inside the channels in the October-April period and a progressive drought period occurs between May and September (seasonally flooded wetland sensu Cowardin et al. 1979), corresponding to local summer aridity period (Blasi 1994;Mesomediterranean xeric region;Tomaselli et al. 1977). ...
In a remnant wetland of Central Italy, we carried out a yearly pilot study on some aspects of diving ecology and behavior of the little grebe (Tachybaptus ruficollis). During the 2005 period, this species occurred in the study area from October to June, when the maximum water depth in wetland channels was deeper than 30 cm. Density of the little grebe resulted significantly correlated with maximum water depth in channels. In diving sampling sites the water depth was 77.62 cm in average (±28.89) and, during the study period, it was not correlated with maximum water depth in channels. In January-March period, when maximum water depth was deeper than 110 cm in average, the median values of water depth in diving sampling sites was significantly lower, when compared to the median values of water depth in channels. Water depth in sampling sites appeared relatively constant around a yearly cycle and independent to maximum water depth in channels. These data corroborate the hypothesis that in a wetland with a heterogeneous pattern of water depth, little grebe individuals avoid diving in wet areas with too deep water (i.e., [1 m) because in these conditions individuals could face a too high energetic cost for acquiring food resources.
... Water level is variable in space and in time. Around a yearly cycle, water depth is maximum inside the channels in October-March period and no water is present in the June-October period (seasonally flooded wetland sensu Cowardin et al. 1979). When the water level in the channels is lower than 100 cm depth, during the period May-October, reed beds and rush beds surrounding them tend to dry out. ...
In wetlands embedded in reclaimed lands, water level in channels is actively managed. Here, we evaluated the effect of a seasonal water level decrease on an assemblage of five water-obligated bird species (Tachybaptus ruficollis, Anas platyrhynchos, Rallus aquaticus, Gallinula chloropus, Fulica atra), at the level of their density, diversity index and consuming biomass in a Mediterranean remnant wetland during two breeding seasons (2004 and 2005). Following the water level dwindling in wetland channels, total density decreased inducing a progressively significant drop in diversity index and consuming biomass from late March to June. Median values of density were significantly higher when water level was higher than 100 cm in channels. Consuming biomass showed a decrease of one order of magnitude from March to June. When the water depth in channels was lower than 100 cm, the reed beds, rush beds and flooded meadows surrounding them dried out reducing the habitat suitability for the water-obligate species. This induced a local population decline in this assemblage of sensitive sedentary species. Despite the water persisting in channels until late spring, it could not represent a suitable condition for water-obligate bird species, also if the water level was apparently high (i.e., 100 cm or less).
... Flow from surrounding areas is scarce. Water depth varies with the seasons: from October to March the flood level reaches the maximum value (70 cm), while from June to October is reduced to form some areas of muddy soil or shallow ponds (Battisti et al. 2006;Causarano and Battisti 2009;Zacchei et al. 2011; seasonally flooded wetland sensu Cowardin et al. 1979). The study area shows a specific, seminatural patchiness, composed by different patches of reed beds, dominated by Phragmites australis (Cav.) ...
We compared a set of uni-varied diversity metrics of a guild of water-related birds (hereafter 'waterbirds') before and after a wetland restoration carried out on uncultivated (reclaimed) lands. Over a period of five years, we observed a restart of seasonal waterbirds dynamics after wetland restoration by flooding of abandoned croplands, with a significant increase in all metrics of diversity, more evident in autumn-winter periods. Seasonal thresholds were evident before (2017-2018) and after (2018-2019) the flooding. These dynamics appeared irregular, probably for a different inter-annual suitability of the flooded meadows due to local ecological factors (e.g., change in meteorological regime and in rush-bed vegetation cover). Rarefaction curves, both for richness and diversity, showed how the waterbird community moved towards a greater complexity. Flooded meadow restoration, particularly favoured wintering species in Mediterranean sites, which explained the strong fluctuations in total abundance. At the species level, Northern Lapwing (Vanellus vanellus), absent before restoration, was the most abundant species after flooding, using flooded meadows with its gregarious behaviour. This 'crowding' may be explained also for a lack of similar habitats in the surrounding. Other dominant species (Anas platyrhynchos, Ardea cinerea, Egretta garzetta) showed a significant increase after restoration. Standardized before-after monitoring on medium term time periods seem suitable to evidence inter-annual season dynamics in diversity metrics of waterbird assemblages.
... Study sites included other wetlands on the REOC and nearby wetlands where landowners granted access to their properties. Most sites (n = 18) were classified as palustrine unconsolidated bottom wetlands; six sites were classified as palustrine emergent, one was palustrine scrub-shrub, and four were palustrine aquatic bed (Cowardin et al. 1979;Lozon 2021). Wetlands varied from 0.04-1.71 ...
Wetland management practices often alter habitat characteristics to improve the function of the wetland (e.g., removing emergent vegetation for aesthetics or dredging for fish stocking), potentially at the cost of reducing habitat quality for wetland-dependent species such as freshwater turtles. We identified wetland and surrounding landscape characteristics related to painted turtle (Chrysemys picta) and snapping turtle (Chelydra serpentina) relative abundance and snapping turtle movement among wetlands. We surveyed turtles at 29 wetland sites (0.04-1.71 ha) in a mixed-use watershed in north-central West Virginia, USA, where hardwood forests and wetlands have been heavily fragmented by agriculture and roads. We also applied radio transmitters to 33 adult snapping turtles (17 females and 16 males) across 17 wetlands. Snapping turtle relative abundance was best estimated with mean substrate depth, mean wetland depth, and minimum distance from roads. Painted turtle relative abundance was best estimated with the null model. We documented movement among wetlands for 22 snapping turtles (67%), including 10 females and 12 males. The probability of inter-wetland movement decreased with increased minimum distance from wetlands. Our results suggest that the focal turtle species readily used shallow, mucky wetlands with deep substrate and that increasing the density of wetlands could increase snapping turtle population connectivity. Managers could consider restoring a diversity of wetland types that result in reduced travel distance between wetlands and that collectively have characteristics conducive to multiple species.
... Un milieu humide est une terre où la nappe phréatique est au niveau, près de ou au-dessus de la surface suffisamment longtemps pour promouvoir la formation de sols hydriques, ou pour supporter la croissance d'espèces hydrophytes (Cowardin et al., 1979). Les milieux humides peuvent donc se trouver en milieu aquatique ou en milieu terrestre, et en position riveraine ou non riveraine. ...
Freshwater and wetland ecosystems of the boreal forest represent rich ecosystems forming complex
network of lakes, rivers, and wetlands. Many wildlife species use and depend upon these habitats for
their life cycle. In addition to this high biological importance, aquatic and riparian habitats are used by
humans for a variety of activities, of which hydroelectricity, cottage resorts, and ecotourism. Although
several scientific works have proposed forest management principles for those areas, there are few
examples of their implementation, perhaps because few have been done or because they have not
been reported in the literature. A problem with these forest management practices is that the efforts
could be lost if we do not insure that other users do not mitigate the efforts of foresters by converting
the areas protected from harvest into resorts or other potential conflicting uses.
A solution to this problem could be to zone using an approach inspired from the triad. This means
three different land use categories: protected ecosystems, intensive human use areas, and multifunctional
areas under ecosystem management. We have used this approach at the Forêt
Montmorency (Québec), a 67-km² teaching, demonstration, and research forest under the
responsibility of Laval University. In this territory, we classified the aquatic, wetland, and riparian areas
according to a recently developed classification system based on numerical forest maps. Our results
revealed that in this hilly and forest-dominated landscape, aquatic habitats are rare (1.3% of the study
area) and altered, mainly by dams constructed for log-driving and now maintained for recreation
purposes and by recreation activities. However, there seems to remain sufficient proportions of intact
ecosystems of all types identify to implement a conservation approach based on coarse filter, which
aims at protecting 20% of all primitive ecosystem types.
... Wetlands in the county are critical in controlling flooding, and in protecting hydrologic cycle functions such as groundwater recharge, flow attenuation, and maintenance of baseflows." The SMC classified each historic and existing wetland (or water body) polygon according to the U.S. Fish and Wildlife Service's official classification system for wetlands and deepwater habitats (FGDC 2013, adapted from Cowardin et al. 1979). For each polygon, SMC expanded on the Cowardin descriptors by adding hydrogeomorphic descriptors for landscape position, landform, water flow path, and waterbody type ("LLWW descriptors" from Tiner 2011a) that focus on abiotic properties that are key to predicting wetland functions. ...
The Lake County Stormwater Management Commission (SMC) is a planning and regulatory agency that coordinates stormwater management activities on a countywide basis. The SMC staff provide technical assistance, local knowledge and problem-solving skills to coordinate the stormwater activities of over 50 local jurisdictions to enhance water quality, reduce flood damages, mitigate flood hazards, and restore/enhance the natural drainage system. Wetlands are an important, natural component of the county’s stormwater management system. On August 14, 2001, Lake County amended its Watershed Development Ordinance (WDO) to regulate development of isolated waters and wetlands. The amendment was in response to the Supreme Court’s January 9, 2001, decision in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers that most isolated waters and wetlands could no longer be regulated under the federal Clean Water Act. “Isolated Waters of Lake County” (IWLC) are defined as “All waters such as lakes, ponds, streams (including intermittent streams), farmed wetlands, and wetlands that are not under U. S. Army Corps of Engineers jurisdiction” .
... It was applicable at the refuge, regional, and national level and conducive to systematic usage and economies of scale. Furthermore, it was tailored to use with the FWS's wetland classification system (Cowardin et al. 1979). (Note: In 1996 the updated Cowardin et al. system was designated as the national standard -"FGDC-STD-004" -for wetland classification; FGDC 2013). ...
The U.S. National Wildlife Refuge System (Refuge System) includes 173 marine coastal refuges that provide exceptional benefits for fish and wildlife as well as valuable ecosystem services to local and regional economies. Many of these refuges have historic and cultural significance. For example, Pelican Island (FL) was the first national wildlife refuge (NWR), Chincoteague NWR (VA) has the visitation of a national park, and Dungeness NWR (WA) remains a stronghold of tribal culture. Most coastal refuges, with notable exceptions primarily in Oregon and Alaska, also have gently sloping shoreline topography, leaving them vulnerable to sea-level rise.
... For each delineated wetland, we then used summaries of long-term weather data and assessment of wetland persistence across a time series of satellite images to group wetlands into one of three hydroperiod categories: 1) permanent (present in all years), 2) semi-permanent (not present in at least one dry year), and 3) temporary (only present in wet years; Albanese and Davis 2013). Within each hydroperiod Page 4 of 14 category, we used in-field assessments to further designate each wetland as one of five wetland types: 1) lacustrine, 2) palustrine, 3) riverine, 4) sheet-water, and 5) water treatment ponds (Cowardin et al. 1979). ...
Wetlands provide many ecosystem services and functions, including critical stopover habitat for numerous migratory bird species. Yet, loss and degradation of wetlands due to land use and land cover changes have greatly reduced wetland extent worldwide, leading to declines of many migratory shorebirds globally. In the Western Hemisphere, wetlands of the North American Great Plains provide important stopover habitat for shorebirds; however, much remains to be learned about shorebird habitat use during stopovers in this region, including species‐specific associations with landscape‐scale wetland availability and characteristics of individual wetlands. To improve understanding of shorebird habitat use during migration, we conducted shorebird surveys at > 14 000 wetlands throughout Oklahoma, USA, from 2007 to 2009. For 16 shorebird species, we analyzed associations between observed abundance and wetland variables, including within‐wetland characteristics and availability of wetlands at multiple spatial scales surrounding survey locations. We found that the scale at which observed abundance of shorebirds was associated with wetland extent varied among species; 10 species responded most strongly to wetland extent at the 500 m scale, but 5 species and 1 species responded most strongly at 1000 and 2000 m scales, respectively. Observed abundance for most species was generally associated with higher wetland density at broad scales, presence of extensive shallow water, more usable area, and limited vegetation within wetlands, yet there was considerable interspecific variation in the strength and in some cases direction of effects of these within‐wetland characteristics. This interspecies variability highlights the importance of conserving a variety of wetland types with differing characteristics that support the entire shorebird community during migration. By informing optimal habitat requirements for shorebirds during a critical stage of their annual cycle, knowledge gained about species‐specific habitat needs from studies like ours can assist with development of conservation and management strategies that contribute to halting and reversing global shorebird declines.
... Wetlands are transitional areas between terrestrial and aquatic systems sharing properties with the both (Cowardin et al., 1979). The presence of water table at or near the surface of land is the main factor governing wetland ecosystem (Ramsar Convention Secretariat, 2016). ...
Earth observation (EO) technology offers enormous opportunities to assess the magnitude and patterns of spatial variability in wetlands over time. This study aims to assess the spatial and temporal changes in the wetlands of the Kashmir valley using multiple remote sensing satellite data products, Geographic Information System (GIS), and field observations. Moreover, role of major factors operating at different time scales including regional geology, climate, and human activities in driving the wetland change is presented. The dynamics of the wetlands are illustrated in the occurrence, seasonality, and recurrence of surface water, land cover transitions and loss patterns particularly for the period from 1984 to 2021. Constituting about 3% (495 Km²) of the total area, substantial and variable patterns of seasonal and annual changes are exhibited by the wetlands. The main transitions of the water surface reveal that 2% of the area has changed from permanent to seasonal; 8% is lost; 15% is new seasonal; 0.12% is permanently lost; and 0.3% is new permanent. About 22% of the area reveals increase in the intensity of water surface occurrence, whereas 44% shows no change, and 34% exhibits decrease. Bathymetric analysis suggests that the average depth of the wetlands ranges between 0.6 and 16.6 m. In general, alpine wetlands are relatively deeper and mostly static in their structure whereas those in the floodplain are shallow, fragmented, and showing signs of depletion during the assessment period. The results of this assessment will inform the policy on conservation and sustainability of wetlands in the Kashmir Himalaya.
... In contrast, C-CAP is produced using data and methods similar to those used to develop the global mangrove datasets. Within both the NWI and C-CAP data, there are Estuarine Scrub-Shrub Wetland and Estuarine Forested Wetland classes (sensu Cowardin et al. 1979), which can potentially be used to identify mangroves closer to the center of their distribution (e.g., south and central FL). However, these classes are not reliable indicators of mangrove distribution near range limits in north FL, LA, and TXs. ...
Global climate change is leading to large-scale shifts in species' range limits. For example, rising winter temperatures are shifting the abundance and distributions of tropical, cold sensitive plant species towards higher latitudes. Coastal wetlands provide a prime example of such shifts, with tropical mangrove forests expanding into temperate salt marshes as winter warming alleviates past geographic limits set by cold intolerance. These rapid changes are dynamic and challenging to monitor, and uncertainty remains regarding the extent of mangrove expansion near poleward range limits. Here, we synthesized existing datasets and expert knowledge to assess the current (i.e., 2021) distribution of mangroves near dynamic range limits in eastern North America. Each grid cell has a resolution of 0.125 degrees, or approximately 14 x 16 km, within which the presence or absence of mangrove has been independently determined using existing datasets and expert knowledge. The data release can be found at this url: https://www.usgs.gov/data/mangrove-distribution-southeastern-united-states-2021#publications
... GIWs are mostly classified based on the dominant vegetation cover, such as marsh, flatwoods or cypress dome wetlands [4,[7][8][9]. Numerous studies of GIWs have investigated various aspects, including evapotranspiration (ET), groundwater recharge, biomass growth, water quality, and generally interactions between groundwater and surface water, storage capacity, and biochemistry [10][11][12][13][14][15]. Despite these investigations, research on quantifying their hydroperiod storage characteristics and measured discharges from these wetlands remains scarce [16]. ...
Geographically isolated wetlands (GIWs) play a critical role in regional hydrology, streamflow, groundwater recharge, evapotranspiration, and water quality. Despite their importance, research on quantifying discharges from these wetlands remains scarce. This study focuses on the hydrological characterization of GIWs in W-C Florida, a region where they cover a significant proportion of the land surface. The paper introduces a new procedure for developing Stage–Storage–Discharge (rating) characteristics essential for deterministic hydrological modeling in larger geographic areas. The approach synthesizes and extends previous research methodologies and offers simplified key modeling coefficients (m and n), which act as intelligent calibration knobs. These coefficients, when coupled with easily derivable physical attributes such as areas, slopes, and elevations, allow for the accurate simulation of downstream discharge timings and magnitudes, including flood behavior. The proposed method was tested using observational data from well-calibrated models. The results indicated a relative error of −7.2% for stage–storage and 15% for stage–discharge. GIS-based techniques were evaluated against surveyed data, and the results showed an accuracy of 0.16 m (0.52 ft) in estimating both the invert elevation and the maximum depth of GIWs. This effort will ultimately contribute to a better understanding and management of these critical ecosystems.
... Study sites included other wetlands on the REOC and nearby wetlands where landowners granted access to their properties. Most sites (n = 18) were classified as palustrine unconsolidated bottom wetlands; six sites were classified as palustrine emergent, one was palustrine scrub-shrub, and four were palustrine aquatic bed (Cowardin et al. 1979;Lozon 2021). Wetlands varied from 0.04-1.71 ...
Successful wetland restoration depends on the development of the vegetation community post-restoration. Woody vegetation provides functional and structural support to the wetland ecosystem and community development post-restoration dictates restoration outcomes. We investigated basal area, stem density, and species richness of woody vegetation in 40 restored wetlands across West Virginia, USA, ranging in age from 1 to 29 years post-restoration. We aggregated field-collected data into eight indicators at the site scale and investigated stem size distribution to describe the overall woody vegetation community. Generalized linear regression shows native species richness slightly declined as wetland site age increased. In contrast, the total basal area increased over time since restoration. Total stem density did not vary by age. Regardless of age, all sites were dominated by woody vegetation with a stem diameter < 9.1 cm, whereas the frequency of stems > 9.1 cm increased as wetland age increased. This study demonstrates that the development of woody vegetation post-restoration occurs over decades in central Appalachian wetlands and shows the diverse conditions between restoration sites.
... Los humedales son ecosistemas que por su origen, forma, biodiversidad, sistema hídrico y biogeoquímico se clasifican como únicos, también se consideran ecosistemas de transición entre los sistemas acuáticos y terrestres (Cowardin et al., 1979), e intervienen directa o indirectamente en el ciclo global del agua (Convención de Ramsar sobre los Humedales, 2018). Los servicios ecosistémicos que brindan los coloca en una parte fundamental para la sustentabilidad de algunas sociedades, pues de ellos se obtienen productos pesqueros, algas, arroz, fibra y otros insumos directos e indirectos. ...
Los servicios ecosistémicos de los humedales son fundamentales para la sustentabilidad de las sociedades por su aporte alimentario y regulación del clima; su gradual deterioro agudiza la crisis ambiental y disminuye la calidad del agua. Los sitios Ramsar fueron creados para la protección de los humedales del Planeta, con el objetivo de preservar la integridad y el mantenimiento de sus características biológicas. Este estudio describe la situación del Sitio Ramsar Núm. 1981 ubicado al noreste de México. Con apoyo de imágenes con vista satelital y mapas de uso de suelo, se contabilizó el cambio de uso de suelo por un periodo de 44 años, analizado en tres instantáneas temporales: 1975, 2003 y 2019. Se comprobó una reducción substancial del humedal y su zona de influencia. Se registró una pérdida de 84 % en área inundable, el matorral decreció 36 % y la zona agrícola y el pastizal incrementaron su superficie en 547 % y 284 %, respectivamente. Dicho aumento ocurrió a expensas del área inundable, posiblemente causado por los prolongados periodos de sequía durante las últimas décadas. Es importante reconocer que en México no se ha legislado específicamente para la protección de los humedales, por lo que decretar un sitio Ramsar no es suficiente para frenar o revertir los procesos de deterioro ambiental. Es necesario mejorar la gestión de las leyes vigentes y desarrollar un plan de manejo adaptativo sujeto a los cambios hídricos provocados por el cambio climático, el manejo inadecuado de las cuencas y la falta de cobertura natural.
... The typology that accompanies the Ramsar definition incorporates geologic/geomorphic, hydrologic, and biotic features and processes that are the basis for other classification systems (e.g. Cowardin et al., 1979;Brinson, 1993;Warner and Rubec, 1997) to describe 43 wetland types across 13 coastal/marine, 20 inland, and 10 human-made environments (Refer to Appendix 1 for wetland types and codes) (Ramsar Convention Secretariat, 2010a). ...
... The South African Classification System for Wetlands and other Aquatic Ecosystems [18,19] uses a hydrogeomorphic (HGM) approach to classification and distinguish between the lacustrine and palustrine type only at the lower levels of the tiered Classification System for Wetlands and other Aquatic Ecosystems as descriptors and not as biomes. In addition to the deeper lacustrine wetlands defined by Cowardin et al. (1979), South Africa also includes shallower lacustrine systems. Therefore, depending on the depth of a lacustrine wetland, it can be typed as either a lake or m inundated to a maximum depth at the average annual low-water level of an open waterbody) or a littoral lacustrine wetland (<2 m) [18,19]. ...
This chapter provides a definition of the wetland types where the aquatic macrophytes described in this Atlas occur. There are also wetlands where plant species occur that are not considered aquatic macrophytes within the context of this Atlas, e.g., intertidal estuarine and marine wetlands. The chapter also mentions some of the main human interference impacts on macrophyte diversity in different wetland types.
Extended Abstract
Introduction
Wetlands are considered valuable resources of the environment. Despite the importance of wetlands, they are currently threatened by intensive water harvesting for irrigation, industrial development, deforestation, construction of dam reservoirs, and changing rainfall patterns. Monitoring can determine the changes in the location, extent, and quality of the wetland and therefore plays an important role in the maintenance and protection of the wetland. Ecosystem monitoring with remote sensing methods offers the advantage of difference, frequent and uniform coverage of large areas. The study of effective parameters or up-to-date maps that show spatial and temporal changes in the sub-basin of Horul Azim Wetland is not available. Therefore, considering that currently, this wetland is struggling with various problems to continue its survival, the purpose of this research is to use Google Earth Engine and satellite data to study the process of wetland changes.
Materials & Methods
This study was done on the platform of Google Earth Engine open source system. In this study, the data of water area, vegetation cover, precipitation, evaporation, and surface temperature were coded in the Google Earth Engine system in a standard way and their time series was obtained. Also, the NASA GRACE data analysis tool (DAT) was used for time series of groundwater levels. In this research, the Mann-Kendall test and Spearman's correlation were used in order to evaluate the changes in different parameters. In this research, the period from 2000 to 2022 was considered to investigate the trend of the data according to the available time range of the data. Finally, to check the fact that the changes in the zones were affected by floods, the data of the Global Surface Water of Water Occurrence (GSWE) probe was used.
Results, discussion, and conclusion
The results of the analysis graph of the water area data trend showed that from 2007 to 2019 the water area trend is increasing, with 2007 being the minimum year and 2019 being the maximum year, and the reason for this was the 90% water withdrawal of the Hor al-Azim wetland in the Iranian part. Also, the reason for the increase in the water area in 2017 is heavy rains that lead to floods and overflowing of the Karkheh dam in the sub-basin of the Hor al-Azim wetland. In 2017 and 2020, 2021, the water area shows a significant increase, which is due to the change in climatic behavior and the occurrence of floods in these years. Finally, the trend of the blue zone will be downward until July 2022. The results of a careful analysis of the data trend by the Mann-Kendall test showed that the trend of the available time period was observed. Kendall's tau value also confirms the increasing trend. It seems that the increasing trend of the water area in the years 2019 to 2021 in this study using the Google Earth Engine system is the result of the floods of the last few years, that Considering only this parameter and these data leads to errors in the study and investigation of the condition of Hor-al Azim wetland. No significant trend was observed in the time series of vegetation cover, but according to the positive Mann-Kendall vegetation cover statistic, one of the causes of the non-significant decrease in the groundwater level could be the increase of pastures and agricultural lands. Kendall's tau value for the surface temperature also showed a negative value (-0.24). According to this result and the sensitivity of the evaporation parameter to temperature, we can point to the role of this parameter in reducing evaporation in the sub-basin of the Hor al-Azim wetland. The northwest and southeast regions have the highest temperature up to a part of the central region of the sub-basin. The western part, which includes the border of the Hor al-Azim wetland, has the lowest temperature, and most of the central part has the lowest temperature, one of the causes of which can be the presence of vegetation and the development of agricultural lands. The time series graph of precipitation showed that the parameter of precipitation in the years 2017 to 2020 had an upward trend, which led to recent floods in the studied area. The results of the Mann-Kendall test for the general trend of evaporation and transpiration parameters, ground surface temperature, and precipitation in the sub-basin of the Hor al-Azim wetland did not show a significant trend. Using the Global Surface Water Explorer (GSWE) data, the occurrence of water, the intensity of water changes, and the seasonal change of water on the wetland were studied for the period of 1984-2021. The study of this dataset confirmed the human interference (creating the Karkheh Dam and draining its lake) and the occurrence and effects of the flood on the sub-basin of the Hor-al Azim wetland. The results of Spearman's correlation test also showed that climate changes such as changes in precipitation patterns and human activities can become factors that affect the surface of the water body of Hor al-Azim Wetland. The results of this research can be used in the management of Hor al-Azim wetlands and wetlands with similar conditions.
Bihar, situated in the eastern part of India, possesses a repository of 21,998 wetlands, covering an extensive area of 403,209 hectares. These wetlands, known for their ecological richness, have a crucial role in offering a wide range of ecological services. Their diverse functions, which include hydrological processes like recharging and discharging groundwater, controlling floods, and regulating water flow, highlight their importance. However, there has been a lack of comprehensive research on wetlands of Bihar, State. This paper provides a thorough analysis of Bihar's wetlands. It also explores the social and environmental benefits that they provide, highlighting their pivotal role in maintaining the ecological equilibrium and local economies of the region. Furthermore, this paper dissects the various threats faced by these wetlands, stemming from human activities and environmental changes. In addition to the ecological perspective, this study investigates the socio-economic conditions of communities living near these invaluable wetlands. It critically assesses their reliance on wetland resources and the consequences of wetland degradation on their well-being.
The Moroccan coastline extends for 2,130,80 km on the East Atlantic an Western Mediterranean coasts. It shows a high diversity of estuaries, bays, beaches and steep coasts. Despite its ecological, economic, and recreational importance, Morocco does not have a comprehensive inventory of its coastal landscapes. This study attempts to develop a primary classification of Moroccan steep coasts, based on a descriptive inventory of these landscapes, using 12 morphodynamic criteria that we mainly measured on satellite images. To achieve the said classification, we organized the steep coasts and the criteria in a binary matrix, which we treated with the hierarchical ascending classification method (CAH) and Factorial Correspondence Analysis. The results of this treatment provides a clustering scheme where we distinguish six different groups of cliffs, each of them being subdivided to 2 or 3 subgroups. Three categories of criteria appear as determinant in this classification: morphometric (length, area, and elevation), geologic (dominant rock and geologic eras), hydrodynamic (swells), and aerodynamic (wind). However, the two first criteria have the most significant influence on the classification.
This classification, mainly based on satellite data, remains preliminary and requires improvements such using some field data. Finally, the raw and compiled data collected in this study constitute database composed of 175 cliffs, described using parametric criteria; this database is a contribution to the national wetlands inventory and is essential to promoting their conservation as well as management.
This extension note describes the basic ecological features of wetland ecosystems. It is a foundational document that provides important concepts and background information.
The structure of bird assemblages recorded in breeding and wintering period in a Mediterranean wetland of Central Italy was studied in order to evaluate their seasonal changes and the influence of land cover on their parameters. We identified three habitat macro-types, according to a man-disturbed gradient (from natural to man-made macro-types). Bird assemblages showed differences in relation to season and habitat type, either at quantitative (species richness, diversity index) or qualitative level (species composition and turnover, similarity). In winter, we obtained the higher values of mean species richness, Margalef richness, Shannon diversity, and β-diversity. The dendro-gram of similarity showed a major clear-cut division between seasons, and a secondary division among habitat macro-types. In winter, assemblages were more rich and diverse, with a high turnover among point counts. The semi-natural habitat macro-types showed always the higher values of these indexes, with the exception of the β-diversity, which showed the highest value in winter but the lowest in the breeding period. The high mean values of richness (α-diversity) of the semi-natural habitat macro-types, especially in the breeding period could be mainly explained by the 'intermediate disturbance hypothesis'; on the contrary, differences in turnover (β-diversity) between the seasons are mainly due to seasonal changes in habitat heterogeneity of this habitat macro-type (from an arid homogeneous pasture to a patchy flooded one). A pattern of intermediate disturbance was evident at mean species richness level (significant values) but not at diversity index level (not significant values). These results could imply specific strategies for the management of small wetlands, focused on maintaining a regime of natural (flooding) and man-made (grazing) disturbances.
En 2016, un sector del delta del Paraná fue registrado en los términos de la Convención Relativa a los Humedales de Importancia Internacional, especialmente como Hábitat de Aves Acuáticas (UNESCO 1971). Esa categorización requirió la movilización del concepto de humedal dentro de la estructura estatal. El propósito de este trabajo es indagar sobre el contexto de producción y significado del concepto científico de humedal, esencial para caracterizar y enmarcar el sitio en dicha Convención. Mediante una metodología cualitativa, basada en el análisis documental y en entrevistas semiestructuradas a actores clave (funcionarios y expertos), se describe el desarrollo epistémico del concepto en el mundo y se caracterizan los procesos de admisión y adaptación en Argentina, así como su vinculación con la designación del sitio delta del Paraná. Como resultado, se observa que en el ámbito científico se estabiliza la noción de humedal, traducida en una definición vigente en un tratado internacional y en una definición consensuada y adaptada a la situación de los humedales en Argentina. La acción de los expertos y la identificación del delta del Paraná como humedal promovió la inscripción del sitio en la lista establecida por la Convención de Ramsar.
Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions.
Supplementary Information
The online version contains supplementary material available at 10.1007/s13157-023-01722-2.
Accurate, unbiased wetland inventories are critical to monitor and protect wetlands from future harm or land conversion. However, most wetland inventories are constructed through manual image interpretation or automated classification of multi-band imagery and are biased towards wetlands that are easy to directly detect in aerial and satellite imagery. Wetlands that are obscured by forest canopy, that occur ephemerally, and that have no visible standing water are, therefore, often missing from wetland maps. To aid in the detection of these cryptic wetlands, we developed the Wetland Intrinsic Potential (WIP) tool, based on a wetland-indicator framework commonly used on the ground to detect wetlands through the presence of hydrophytic vegetation, hydrology, and hydric soils. Our tool uses a random forest model with spatially explicit input variables that represent all three wetland indicators, including novel multi-scale topographic indicators that represent the processes that drive wetland formation, to derive a map of wetland probability. With the ability to include multi-scale topographic indicators that help identify cryptic wetlands, the WIP tool can identify areas conducive to wetland formation while providing a flexible approach that can be adapted to diverse landscapes. For a study area in the Hoh River watershed in western Washington, USA, classification of the output probability with a threshold of 0.5 provided an overall accuracy of 91.97 %. Compared to the National Wetlands Inventory, the classified WIP tool output identified over 2 times the wetland area and reduced errors of omission from 47.5 % to 14.1 % but increased errors of commission from 1.9 % to 10.5 %. The WIP tool is implemented as an ArcGIS toolbox using a combination of R and Python scripts.
Wetlands are water-logged depressions bounded by elevated landscape; its environments and potential usage defined its specific diversity. This research seeks to characterize three wetlands designated as; Kyrika Waterfall Wetland (KWW-Basin), Ahonfena Stream Wetland (ASW-Basin) and Apitikoko-Awura Upstream Wetland (AUW-Basin) at Obuasi, Ghana. The specific objectives are to; (1) assess the drainage holding capacity of the wetlands using bathymetry methods, (2) classify the wetland using existing classification schemes with vegetations data. Site maps for the study were generated from aerial photographs. Clinometer semi-extensible pole (Clino-SEMP), water marks on trees, rocks and hydrophytic plants were used for bathymetry survey, while nested quadrants sampling method was used to sample herbaceous plant, shrubs and trees in the strata. Flora was categorized into wetness index, based on flora coefficient of wetness and species dominance. Physicochemical status of soil and water samples were analyzed, using PCE Redox meter model PCE-PHD 1-R on the field. Bulk density and porosity of cored soil samples were analyzed for various depths at the Laboratory. KWW-Basin, ASW-Basin and AUW-Basin are − 669,240 m3, − 232,997 m3 and − 1,026,187 m3; Similarly, geomorphology is characterized by riverine nature as; upper perennial, intermittent and lower perennial, while wetness indexes are; 0.599, − 0.039 and 0.689, respectively. Lowest wetness index corresponds to highest wetness plant taxa, moisture content, porosity and least bulk density. Finally, classifications based on standard criteria, qualify KWW-Basin as Inland Riverine Upper Perennial Facultative Upland Wetland; AUW-Basin as Inland Riverine Intermittent Facultative Wetland-Upland Wetland; and ASW-Basin as Inland Riverine Lower Perennial Facultative Upland-Obligate Wetland.
The future of wetland bird habitat and populations is intrinsically connected with the conservation of rangelands in North America. Many rangeland watersheds are source drainage for some of the highest functioning extant wetlands. The Central and Pacific Flyways have significant overlap with available rangelands in western North America. Within these flyways, the importance of rangeland management has become increasingly recognized by those involved in wetland bird conservation. Within the array of wetland bird species, seasonal habitat needs are highly variable. During the breeding period, nest survival is one of the most important drivers of population growth for many wetland bird species and rangelands often provide quality nesting cover. Throughout spring and fall, rangeland wetlands provide key forage resources that support energetic demands needed for migration. In some areas, stock ponds developed for livestock water provide migration stopover and wintering habitat, especially in times of water scarcity. In the Intermountain West, drought combined with water demands from agriculture and human population growth are likely headed to an ecological tipping point for wetland birds and their habitat in the region. In the Prairie Pothole Region, conversion of rangeland and draining of wetlands for increased crop production remains a significant conservation issue for wetland birds and other wildlife. In landscapes dominated by agricultural production, rangelands provide some of the highest value ecosystem services, including water quality and wetland function. Recent research has shown livestock grazing, if managed properly, is compatible and at times beneficial to wetland bird habitat needs. Either directly, or indirectly, wetland bird populations and their habitat needs are supported by healthy rangelands. In the future, rangeland and wetland bird managers will benefit from increased collaboration to aid in meeting ultimate conservation objectives.
The vegetation and peatland types of the Lake Agassiz Peatlands Natural Area are related to topography, waterflow patterns, water chemistry, and the evolution of the landscape as recorded by peat stratigraphy. Eight peatland types are distinguished: (1) minerotrophic swamp, (2) weakly minerotrophic swamp, (3) string bog and patterned fen, (4) forest island and fen complex, (5) transitional forested bog, (6) semi-ombrotrophic bog, (7) ombrotrophic bog (raised bog), and (8) raised bog drain. Consistent differences in pH, Ca, and Mg were found between waters of contrasting peatland types. These differences agree with the division of peatland types by degree of mineral soil water influence (minerotrophy). A general topographic alignment of vegetation and peatland types agrees with the hypothesis of chemical controls. Vegetation types often have sharp boundaries related to changes in water properties, peat surface configuration, and paths of waterflow. Landscape evolution included five phases: (1) Recession of Lake Agassiz about 11,700 years ago. (2) Organic sedimentation of local basins beginning 11,100 years ago. Aquatic peats eventually covered 6% of the substratum. (3) Development of fens, marshes, and carr during the postglacial warm-dry interval, beginning about 8,000 years ago. These peatlands built the sedge peats that now cover 46% of the substratum. Paludification caused water tables to rise, and most water basins were overgrown. (4) Invasion of minerotrophic swamp forests around the perimeter of the peatland and along substratum ridges, beginning about 5,000 years ago as the climate cooled and precipitation increased. These forests built the basal forest peats that now cover 48% of the substratum. (5) Capture of part of the watershed by Northeast Brook about 3,100 years ago, which caused a water-table divide and mineral depletion, initiated sphagnum invasion, and led to development of the present ombrotrophic raised bogs. As convexity grew, a sharp vegetation and chemical gradient developed along the limit of mineral soil water. Myrtle Lake rose steadily with paludification and now stands 11.8 ft (3.6 m) above the ridge 1 mile (1.6 km) north of the lake. Water tables rose 10-20 ft (3.0-6.1 m) over much of a 70-square-mile (181-km^2) area. This history does not agree with early concepts of succession, which postulate a trend toward mesophytism with peat accumulation. The only @'direction@' here is a possible trend toward landscape diversity.
A study of bottom fauna-substrate relationship conducted on North St. Vrain Creek, Colorado, USA in 1945 was repeated in 1974 to determine changes in the stream environment and in the community structure and standing crop of macroinvertebrates. The stream remains a clear, unpolluted trout stream with soft water of neutral pH. Despite differences in flow, temperature, and riparian vegetation, macroinvertebrate composition was similar to that of 1945; most differences can be attributed to normal year-to-year fluctuations and slight shifts in emergence periods. Total density was less on all substrate in 1974, which is attributed to the higher discharge. Total biomass was comparable except for lower values on bedrock in 1974.
In an attempt to evaluate lake-survey procedures some of the chemical, physical, and biological measurements that have been considered possible indices of lake productivity have been examined in the light of 11 years of lake surveys and 6 years of pond rearing of yellow pikeperch. In Minnesota waters total alkalinity and total phosphorus appear to be the most valuable indices. Nitrogen is usually present in excess; sulphates are of most value in considering waterfowl areas; and chlorides, pH, and dissolved carbon dioxide are of little value in comparing waters and judging potential productivity. Potassium, manganese, and iron concentrations also are discussed. Quantitative plankton and bottom-fauna samples have been found unsatisfactory as productivity indices for ordinary lake surveys, and the distribution and abundance of larger aquatic plants are of greatest value when related to waterfowl management. In estimating the potential productivity and formulating fish-management plans for lakes the structure of the fish population and the nature of the lake basin should be considered.
ty of metal ions in water of precipitation (except in definitely maritime areas) leads to strongly acid reactions both of the water and of the peat in most ombrotrophic peatlands. The vegetation of the ombrotrophic peat- lands, or (in a restricted sense) bogs, is highly specialized, acidophilous, and poor in species of flowering plants. Other types of peatland receive varying quantities of water from mineral soils in addition to precipitation. This water percolates through the surroundings of the peatland and acquires varying amounts of mineral ions in passing through the soil. This minerotrophic peatland is generally termed fen. The minerotrophic influence in the fens always results in a richer and more varied vegetation largely composed of species not present in bogs. This indicates a somewhat better nutritional status and less acid conditions than in the bogs. Some fens are circumneutral and rich in species. Extreme types of these "rich fens" have a high calcium content and abound in calciphilous plants, but there are also fens in which the minerotrophic influence is not sufficient to inhibit the development of a fairly acid reaction; in these the vegetation generally belongs to the "poor fen" type (intermediate between "rich fen" and bog). Even in regions in which they are extensive, peatlands occur mostly as individual bodies that are confined to depressions. The shapes of the peatland bodies are mainly determined by the configuration of the under- lying and surrounding mineral stratum; their hydrotopography is also dependent on climatic factors. Conditions may vary considerably in differ- ent parts of the same peatland. For instance, parts of the surface may be ombrotrophic and other parts of it more or less minerotrophic. Such peatland complexes ere classified as entities -by Cajander in his classic
It is attempted to clearly distinguish between bogs on the one hand and swamps and marshes on the other. The principal elements and factors are listed in Eastern North America where bogs are frequent. This first paper attempts a general outline of the dynamics of bog vegetation in this region and describes the structures of the communities involved. The biotope is considered the smallest piece in the association mosaic and its physical and biological aspects are emphasized. Two recent systems (Küchler's and Dansereau's) are applied to individualize the most important and widespread synecological units. Further studies involving climatic relationships on a geographical scale and phytosociological measurements at the quadrat level will permit a refocusing of some of the phenomena which are described and interpreted here.
Wetland is part of a continuum of land types between deep water and dryland. Only one wetland classification was available for the United States prior to preparation of the new system described here, but numerous regional and special-purpose classifications are in use. The new classification is hierarchical, progressing from five systems (marine, estuarine, lacustrine, riverine, and palustrine) at the most general level to dominance types based on plant or animal communities at the most specific level. The system is currently in use for prototype maps of wetlands of the United States. It is hoped that it may be incorporated into a classification of all land.
An ecological study of the upper Patuxent River, Maryland was made from June 1963 to June 1966 to determine water quality
and distribution of emergent and submergent macrophytes. The area investigated was 25 miles long and extended from Benedict
to Hills Bridge.
Physical and chemical measurements of the aquatic environment determined that: (I) the highest intrusion of salt water was
Hills Bridge and the lowest was Holland Cliffs; (2) a total salinity value of around 0.3 ppt represented the boundary between
fresh and saline water; (3) fluctuation of parameters over 24-hour period reflected biological activity and tidal changes.
The flora was composed of 167 species representing 55 families of vascular plants and 12 species of macrophytic algae.
The salt marsh at Barnstable, Massachusetts, occupies an embayment into which it has spread during the past 4,000 years. It exhibits all stages of development from the seeding of bare sand flats through the development of intertidal marsh to the formation of mature high marsh underlain by peat deposits more than 20 ft deep. Observations and measurements of the stages of its formation are presented. The geomorphology of the marsh is considered in relation to the factors which have influenced its development, i.e., the ability of halophytes to grow at limited tide levels, the tidal regime, the processes of sedimentation, and the contemporary rise in sea level. The rates at which the early stage of development takes place have been determined by observations during a period of 12 years and the time sequence of later stages by radiocarbon analyses.
The Workshop on Critical Problems of the Coastal Zone was held in Woods Hole, Massachusetts, 22 May-3 June 1972. This report represents the professional judgment of the participants on the problems created by man's use of coastal resources. Guidelines and recommendations are presented for actions which can be taken to ameliorate, correct or improve present or predicted deterioration of the coastal environment. The specific conclusions and recommendations of the workshop are summarized in this book. Major chapter headings are: Constraints on man's activities; Nonrenewable resources; Recreation and esthetics; Urbanization and industrial development; Transportation and coastline modifications; Contamination and coastal pollution through waste disposal practices; Strategies and research needs for coastal zone management; Allocating coastal resources and trade off and rationing processes; Structure of management and planning; Legal aspects of the coastal zone; and A systems view of coastal zone management.
Thesis (Ph. D.)--Dept. of Geology, Stanford University. Bibliography: leaves 133-135.
Bibliography: leaves 115-120. Vita. Thesis--North Carolina State University.
http://deepblue.lib.umich.edu/bitstream/2027.42/56315/1/MP070.pdf